Single-Source Contingency

See the ISO New England Inc. Transmission, Markets, and Services Tariff, Attachment G Procedure to Protect for the Loss of Phase II Imports, which describes the process used by ISO New England, New York ISO, and PJM to monitor their respective systems and provide the data required by ISO New England to calculate import limits on the Phase I/II high-voltage direct-current interconnection between it and Hydro-Québec TransÉnergie.

Download a report on single-source contingencies, limits placed on external and generation interfaces in which losing a single piece of equipment could cause a loss of 1,200 or greater megawatts (MW).

The single-source contingency limit is the base limit plus the authorized margin multiplied by the margin sensitivity. The NY Central-East single-source contingency limit is based on the authorized margin divided by the Distribution Factor (0.30). The margin associated with NY Station Voltages has been converted to MW.

Note: The compilation of this data has various origins and is provided for the convenience of the New England market participants. The ISO does not assume responsibility for the accuracy.

 
Single-Source Contingency
Description Timestamp Download
Current - October 03, 2026 10/03/2026 03:16 AM EDT CSV
September 19, 2026 09/19/2026 11:56 PM EDT CSV
September 20, 2026 09/20/2026 11:56 PM EDT CSV
September 21, 2026 09/21/2026 11:56 PM EDT CSV
September 22, 2026 09/22/2026 11:56 PM EDT CSV
September 23, 2026 09/23/2026 11:56 PM EDT CSV
September 24, 2026 09/24/2026 11:56 PM EDT CSV
September 25, 2026 09/25/2026 11:56 PM EDT CSV
September 26, 2026 09/26/2026 11:56 PM EDT CSV
September 27, 2026 09/27/2026 11:56 PM EDT CSV
September 28, 2026 09/28/2026 11:56 PM EDT CSV
September 29, 2026 09/29/2026 11:56 PM EDT CSV
September 30, 2026 09/30/2026 11:56 PM EDT CSV
October 01, 2026 10/01/2026 11:56 PM EDT CSV
October 02, 2026 10/02/2026 11:56 PM EDT CSV